analysis of heavy metals content in water, sediments and fish from the gorgan bay, southeastern caspian sea, iran

the heavy metals concentrations including zinc, copper, lead and cadmium (zn, cu, pb and cd) in water and sediments in gorgan bay and their accumulation in rutilus frisii kutum, acipenser persicus, rutilus rutilus caspicus and cyprinus carpio organs (gills, muscle, kidney and liver) were investigated. there was substantial increase in concentration of heavy metals ingoing from the water to the sediment samples. in water and sediments, the concentration of heavy metal was in the order pb > cd > zn > cu. fish sampleswere collected from gorgan bay and analyzed for heavy metal content of liver, muscle, kidney and gills tissues. the maximum and minimum of heavy metals concentration were recorded in liver and muscle, respectively. the order of heavy metals concentration in different organs of fish samples was liver > gills > kidney > muscle and the order of heavy metals level in muscle, gills, kidney and liver was pb>cd>zn>cu. according to the results, heavy metal concentrations in fish species tissues were well within the limits set by the fao/who recommendations and showed that the fish from investigated region are safety for consumers.